GB632497A - Improvements in or relating to hydro-pneumatic suspension devices and the like - Google Patents

Abstract

632,497. Hydro-pneumatic shock-absorbers. NEWTON, N. B. Feb. 14, 1945, No. 3673. [Class 108 (iii)] In a hydro-pneumatic suspension device of the kind including a piston moving in a substantially enclosed liquid-filled cylinder communicating with a displacement space in which gas under pressure is separated from the liquid by a floating piston, a reservoir containing gas under pressure is connected through a non- return valve to the displacement space so as to maintain a predetermined pressure therein. In the construction described, the displacement space is located between a cylinder 11 and an outer sleeve 13, and contains an annular floating piston 14, the space above which is connected with the reservoir (which is in the form of an air pressure cylinder 15c) by a pipe 15b and non- return valve 15. The displacement space below the floating piston 14 is connected by ports 16 and a valve 17 to the cylinder 11. Movement of the piston 10 of the cylinder 11 is damped by flow of hydraulic fluid through the ports 16 into the lower part of the displacement space and through control passages 10a in the piston. Hydraulic fluid is topped up by gravity feed from a reservoir 23 as described in Specification 632,496, the fluid flowing through a reduced neck-portion 12b of the piston-rod when the latter is fully extended. The air supply pipe 15b may contain a pressurereducing valve 15d to enable make-up of lost air to a predetermined pressure to be carried out automatically whenever the device is fully extended.